This invention relates to a new and improved injector for a syringe needle, and an assembly therefor. More specifically, this invention relates to an injector and assembly for securing to a syringe plunger in a simple manner. The injector is adapted to fire the plunger and needle into the user at a desired angle and depth while the device is maintained in a secure position on the user's body. In addition, the device does not require viewing of the syringe needle by the user, many of whom find this objectionable.
Publications describing syringe injectors for self use are disclosed in U.S. Pat. Nos. 2,856,924; 3,702,608; 3,941,130; 3,880,163; D. 247,576; and, 4,261,358. These devices tend to be complicated in terms of number of parts, and their assembly. Also, many prior art injector devices are designed for use with only a single type, or limited few, syringe injectors. Moreover, the stocking of replacement components is expensive, so that generally the entire device is usually replaced if a component part fails or becomes worn out. In addition, some syringe injectors mount the syringe in an open position, and this is objectionable to many users.
A spring loaded injector device for a syringe and needle is desired having few component parts and a rugged construction. The device should include a trigger system that provides a distinct switching between two well defined upper and lower limits. This in turn will enable the user to preset the device for a predictable needle exposure, and hence penetration, after the injector has been fired.